diff --git a/fs/ceph/mdsmap.c b/fs/ceph/mdsmap.c
index 450a4dc9662e..4f0626753429 100644
--- a/fs/ceph/mdsmap.c
+++ b/fs/ceph/mdsmap.c
@@ -3,6 +3,7 @@
 
 #include <linux/bug.h>
 #include <linux/err.h>
+#include <linux/overflow.h>
 #include <linux/random.h>
 #include <linux/slab.h>
 #include <linux/types.h>
@@ -126,6 +127,7 @@ struct ceph_mdsmap *ceph_mdsmap_decode(struct ceph_mds_client *mdsc, void **p,
 	u8 mdsmap_v;
 	u16 mdsmap_ev;
 	u32 target;
+	size_t export_targets_len;
 
 	m = kzalloc_obj(*m, GFP_NOFS);
 	if (!m)
@@ -224,8 +226,11 @@ struct ceph_mdsmap *ceph_mdsmap_decode(struct ceph_mds_client *mdsc, void **p,
 		*p += namelen;
 		if (info_v >= 2) {
 			ceph_decode_32_safe(p, end, num_export_targets, bad);
+			export_targets_len = size_mul(num_export_targets,
+						      sizeof(u32));
+			ceph_decode_need(p, end, export_targets_len, bad);
 			pexport_targets = *p;
-			*p += num_export_targets * sizeof(u32);
+			*p += export_targets_len;
 		} else {
 			num_export_targets = 0;
 		}